Only turn off my computer when something is wrong with it (like now see here) I also run a 24/7 server on IRC among other places. Restart about once every.....10 days. My record is around 28 days I think.....

i turn mine off, purely because i have no reason to leave it on, butfor the most part, it is off during the day because im at school, it goes on in the afternoon when i get home from school, and goes off when i go to sleep